A novel priority selection system for nuclear power plant

摘要

The priority selection system is an important component of security level instrument control platform for nuclear power plant, the main function of which is priority processing the manual or automatic command with various security levels and driving engineering safety features and field devices, such as pump and valve. Its stability and safety plays a crucial role in the operation of the power plant. The main objective of the present paper is to describe the new nuclear power plant-oriented priority selection system, which is developed independently by China Nuclear Control System Engineering Company. In this system, the control commands from 1E DCS, ECP and DAS systems are transmitted via hardwire, while those from NC DCS are transmitted by fieldbus. The control commands experience priority output to control the field actuators. Meanwhile, in order to control key field devices when failure of the instrument control systems occurs, the issuing interface for native instructions with permissions setting is also offered. The whole system provides collection-feedback functions for field devices, high coverage self-diagnostic functions and periodic test functions for safety systems. Moreover, the feedback information of field devices, the results of self-diagnosis and periodic test will be submitted to DCS of nuclear power plant. In addition, the core part of priority selection system, namely priority selection module, is obtained by pure FPGA technology, which is different from DCS systems and could avoid common cause failure of software effectively.